Page 68 - Read Online

Du et al. Soft Sci 2024;4:35 https://dx.doi.org/10.20517/ss.2024.31 Page 11 of 23

Table 2. The applications of hydrogel actuators in various diseases
Disease type Disease characteristics Trigger conditions Types of hydrogel Ref.
Wound healing (1) Easy to produce (1) Temperature (1) Transdermal [93,94]
(2) Easy to develop complications (2) Light (2) Injection
Diabetic wound healing (1) Hard to heal (1) pH (1) Transdermal [95,96]
(2) Easy to infect (2) pH/glucose
(3) High-sugar wound environment
Periocular disease (1) Complex physiological structure (1)Temperature (1) Transdermal [97,98]
(2) Physiological factors restriction
Periodontal disease (1) Disruptive disease (1) pH/temperature (1) Transdermal [11,99]
(2) Oral environment restriction (2) Temperature (2) Injection
Psoriasis (1) Chronic, autoimmune skin disease (1) Enzyme (1) Transdermal [100,101]
(2) Complex pathogenesis (2) Temperature (2) Injection
Cancer treatment (1) High mortality (1) Temperature (1) Implantation [91,102,103]
(2) Difficult to treat (2) pH
(3) Easy to produce side effects (3) Light
Diabetes mellitus (1) Chronic metabolic disease (1) Glucose (1) Implantation [104,105]
(2) Highly dependent on insulin
Gastrointestinal disease (1) High incidence (1) pH (1) Ingestion [106,107]
(2) Long disease course (2) Enzyme
(3) Harsh treatment environment

Figure 3. (A) Skin wounds of chicken embryo. AAD responds to skin temperature and promotes wound healing through active
contraction [93] . Copyright 2019, AAAS; (B) Schematic of the nanocomposite dressing fabrication and the synergistic treatment of a
bacterium infected wound [94] . Copyright 2020, RSC Publishing; (C) PH-responsive drug delivery of HAO from protamine NPs/HAO
CaAlg hydrogel for a period of 8 h under different pH conditions [95] . Copyright 2019, Springer; (D) The schematic diagram of structure,
pH and glucose-responsive mechanism of PC hydrogel and its application in diabetic foot ulcers and athletic wound healing. PH and
glucose-responsive metformin release [96] . Copyright 2022, ACS Publications. AAD: Active adhesive dressings; HAO: hyaluronan
oligosaccharides; NPs: nanoparticles; PC: PEGS-PBA-BA/CS-DA-LAG.
human body can vary. These factors need further investigation in future studies.

Diabetic wound healing
In the specific pathophysiological environment of diabetic wounds, there are higher requirements for
hydrogel dressings. Diabetic wounds are characterized by disordered inflammation regulation, slow healing,
[111]
susceptibility to infection, and impaired tissue remodeling . Traditional wound dressings have limited
functionality and are not suitable for the diabetic wound healing process. In contrast, stimuli-responsive
hydrogel actuators can adapt to complex wound changes, rapidly monitor and respond to the diabetic
environment, and improve therapeutic efficacy .
[46]